LONDON – Leslie Frazier said he didn’t want to make any snap decisions regarding his quarterback situation.

The Vikings coach said it would be “premature” to name Matt Cassel his starter without reviewing film of Sunday’s 34-27 victory against Pittsburgh and being able to discuss it with his coaching staff.

They’ll have some extra time, with the Vikings on a bye week.

“I don’t know what I would base it on other than what I’ve seen with the naked eye,” he said.

The naked eye, however, revealed quite a bit about Cassel and the entire offense with him at the controls. The Vikings finally married big plays in the passing game with Adrian Peterson’s running to achieve the kind of balance that they believe can force defenses to play them more honest.

Carlos Gonzalez, Star Tribune

Matt Cassel and the Vikings walked off winners in London, defeating the Steelers 34-27.

Cassel passed for 248 yards and two touchdowns, and Peterson rushed for a season-high 140 yards and two touchdowns. The offense scored points on four consecutive possessions at one point and finished with no turnovers for the first time this season.

“When you have the best running back in the NFL, if we can make plays and take advantage of our opportunities in the passing game like we were able to, you can see what happens,” tight end Kyle Rudolph said.

The passing game labored with Christian Ponder under center. Ponder committed seven turnovers (five on interceptions) and ranked 30th in passer rating in three starts before suffering a fractured rib against the Cleveland Browns.

Cassel’s passer rating in his first game in a Vikings uniform — 123.4 — was higher than any Ponder has posted in his career.

“I was really excited about the fact that I was able to help contribute to the team and be accountable to my teammates and get a victory,” Cassel said.

Cassel was far from perfect, but he hit receivers in positions that gave him them opportunities to make plays. He was decisive in the pocket and threw the ball with confidence. Multiple players raved about Cassel’s leadership and the “command” he displays in the huddle.

“He’s a pro’s pro,” left guard Charlie Johnson said. “You can tell he’s a guy who’s been in the fire before. Calm, cool, collected — whatever you want to call it — that’s the way he was all week. Taking command of the huddle and being what a quarterback should be.”

Cassel’s ability to efficiently ignite the passing game provided a snapshot of what the Vikings believe their offense can become. Greg Jennings took a hitch route 70 yards for a touchdown and later added a 16-yard touchdown on a perfectly placed throw by Cassel in the end zone.

Cassel and Simpson also made an instant connection, hooking up for seven catches for 124 yards.

“I firmly believe this offense can be something that’s really to be reckoned with if we can get it going in the passing game like we were able to [Sunday],” Jennings said. “The attention Adrian draws creates a lot of open windows and opportunities in the passing game.”

That’s how it supposed to work, but Ponder never was able to consistently punish defenses for stacking the box to contain Peterson. And the vertical passing game was practically nonexistent.

On Sunday, the Vikings produced a 70-yard catch by Jennings (though most of those yards came from him running after the catch), a 51-yard reception by Simpson and 60-yard run by Peterson.

“We’ve had some big runs, we’ve had some big passes,” Frazier said. “But what we haven’t been able to do is, we’ve had situations where we’ve stopped ourselves with turnovers and drives. It just creates a lot of problems for your team. You can’t get that rhythm that you want to have on offense. We were able to get that going, so it makes it a little bit easier for the play caller when you can put together some drives and finish those drives.”

The Vikings need to build on this performance after they return from the bye. First, Frazier must choose his quarterback. Given the way the offense functioned with Cassel, it’s hard to imagine Frazier sending the veteran back to the bench.

“[Cassel] did a superb job coming in,” Simpson said. “He was very calm and receptive to the role.”